FrankenMini Weblog
PITL Autocross Event #2
Today was event #2 at the Push it to the Limit (PITL) Autocross hosted by the Mazda Sports Car Owners Club. The day started off good enough. Getting used to loading the trailer and getting everything ready so I ended up getting everything done and ready and not feeling rushed.
First run was slow, and I swear the course changed from when I walked it. I thought I had gone off course, turns out I didn't but that moment of feeling lost was good for a second or two. I was running 20psi cold to start. After the first run I got the tire temps, 81F,83F,81F (Approx) across the tire surface. This is pretty consistent across all 4 tires. Now with the tires a little warm I dropped them to 20psi warm. First run, way off the pace at 52 seconds, the fast time of the day was 39 seconds for that first run.
Second run, was much quicker, at least it felt like it. Car did under steer in one of the corners badly, a sweeping left hand 180 degree, car started to plow pretty good. All was good until the stop box where my brakes went away again and I hit the stop box cone. This run was therefore a DNF. Tires on this run were 83F,84F,83F across the face of all 4, give or take 0.5-1.0 degree. The rear driver's side tire seems to get a little hotter in the middle of the others. However this is where my day ended. It started to rain. No brakes, and rain, and that was it, I called it a day. Running without good brakes sucks, running in the rain without good brakes is dangerous.
I managed to bleed to the brakes last weekend using ATE Super Blue, however it doesn't seem to have made a difference. I'm going to order another set of brake pads but I don't think that's the issue. I don't know what the problem is so I've got to start with the pads. I'm currently running Wilwood Polymatrix A pads, the heat profile of this pad is below. At 100F this pad as a Cf (coefficient of friction) of 0.55. These pads should work!
Brakes are my number 1 concern. I'm going to get a set of Street Pads to exhaust that option and if that doesn't work I'll have to take a good look at the hydraulics and calipers. I may order a brake pressure gauge that I can hook up to each line and see what the pressures are at the caliper. As well I may pick up special temperature paint which will change colour when it reaches a given temp. These two tools should tell the story. More to come...
Published at 15:14:41, Saturday, 26.05.07